Stable surface wave plasma source

ABSTRACT

A surface wave plasma (SWP) source is described. The SWP source comprises an electromagnetic (EM) wave launcher configured to couple EM energy in a desired EM wave mode to a plasma by generating a surface wave on a plasma surface of the EM wave launcher adjacent the plasma. The EM wave launcher comprises a slot antenna having at least one slot. The SWP source further comprises a first recess configuration and a second recess configuration formed in the plasma surface, wherein at least one first recess of the first recess configuration differs in size and/or shape from at least one second recess of the second recess configurations. A power coupling system is coupled to the EM wave launcher and configured to provide the EM energy to the EM wave launcher for forming the plasma.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 12/555,080 (Attorney Docket No. TEA-044) filed Sep. 8, 2009 andentitled STABLE SURFACE WAVE PLASMA SOURCE, the disclosure of which isexpressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a surface wave plasma (SWP) source and, moreparticularly, to a stable and/or uniform SWP source.

2. Description of Related Art

Typically, during semiconductor processing, a (dry) plasma etch processis utilized to remove or etch material along fine lines or within viasor contacts patterned on a semiconductor substrate. The plasma etchprocess generally involves positioning a semiconductor substrate with anoverlying patterned, protective layer, for example a photoresist layer,into a processing chamber.

Once the substrate is positioned within the chamber, an ionizable,dissociative gas mixture is introduced within the chamber at apre-specified flow rate, while a vacuum pump is throttled to achieve anambient process pressure. Thereafter, a plasma is formed when a portionof the gas species present are ionized following a collision with anenergetic electron. Moreover, the heated electrons serve to dissociatesome species of the mixture gas species and create reactant specie(s)suitable for the exposed surface etch chemistry. Once the plasma isformed, any exposed surfaces of the substrate are etched by the plasma.The process is adjusted to achieve optimal conditions, including anappropriate concentration of desirable reactant and ion populations toetch various features (e.g., trenches, vias, contacts, etc.) in theexposed regions of substrate. Such substrate materials where etching isrequired include silicon dioxide (SiO₂), poly-silicon and siliconnitride, for example.

Conventionally, various techniques have been implemented for exciting agas into plasma for the treatment of a substrate during semiconductordevice fabrication, as described above. In particular, (“parallelplate”) capacitively coupled plasma (CCP) processing systems, orinductively coupled plasma (ICP) processing systems have been utilizedcommonly for plasma excitation. Among other types of plasma sources,there are microwave plasma sources (including those utilizingelectron-cyclotron resonance (ECR)), surface wave plasma (SWP) sources,and helicon plasma sources.

It is becoming common wisdom that SWP sources offer improved plasmaprocessing performance, particularly for etching processes, over CCPsystems, ICP systems and resonantly heated systems. SWP sources producea high degree of ionization at a relatively lower Boltzmann electrontemperature (T_(e)). In addition, SWP sources generally produce plasmaricher in electronically excited molecular species with reducedmolecular dissociation. However, the practical implementation of SWPsources still suffers from several deficiencies including, for example,plasma stability and uniformity.

SUMMARY OF THE INVENTION

The invention relates to a surface wave plasma (SWP) source and, moreparticularly, to a stable and/or uniform SWP source.

According to an embodiment, a surface wave plasma (SWP) source isdescribed. The SWP source comprises an electromagnetic (EM) wavelauncher configured to couple EM energy in a desired EM wave mode to aplasma by generating a surface wave on a plasma surface of the EM wavelauncher adjacent the plasma. The EM wave launcher comprises a slotantenna having at least one slot configured to couple the EM energy froma first region above the slot antenna to a second region below the slotantenna. A resonator plate is positioned in the second region and has alower surface that includes the plasma surface of the EM wave launcher.The SWP source further comprises a first recess configuration, and asecond recess configuration formed in the plasma surface, wherein atleast one recess of the first recess configuration differs in sizeand/or shape from at least one recess of the second recessconfiguration. A power coupling system is coupled to the EM wavelauncher and configured to provide the EM energy to the EM wave launcherfor forming the plasma, wherein the EM energy comprises an effectivewavelength (λ) of propagation in the resonator plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description given below, serve to explain the invention.

FIG. 1A presents a simplified schematic representation of a plasmaprocessing system according to an embodiment;

FIG. 1B presents a simplified schematic representation of a plasmaprocessing system according to another embodiment;

FIG. 2 presents a simplified schematic representation of a surface waveplasma (SWP) source that can be used for the plasma processing systemdepicted in FIGS. 1A and 1B in accordance with one embodiment;

FIG. 3 presents a schematic cross-sectional view of an electromagnetic(EM) wave launcher according to an embodiment;

FIG. 4 provides a bottom view of the EM wave launcher depicted in FIG.3;

FIG. 5A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 5B presents a schematic cross-sectional view of a portion of the EMwave launcher depicted in FIG. 5A;

FIG. 6A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 6B presents a schematic cross-sectional view of a portion of the EMwave launcher depicted in FIG. 6A;

FIG. 7A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 7B presents a schematic cross-sectional view of a portion of the EMwave launcher depicted in FIG. 7A;

FIG. 8A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 8B presents a schematic cross-sectional view of a portion of the EMwave launcher depicted in FIG. 8A;

FIG. 9A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 9B presents a schematic cross-sectional view of a portion of the EMwave launcher depicted in FIG. 9A;

FIG. 9C provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 9D presents a schematic cross-sectional view of a portion of the EMwave launcher depicted in FIG. 9C;

FIG. 9E provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 10A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 10B presents a schematic cross-sectional view of a portion of theEM wave launcher depicted in FIG. 10A;

FIG. 11A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 11B presents a schematic cross-sectional view of a portion of theEM wave launcher depicted in FIG. 11A;

FIG. 11C provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 12A provides a bottom view of an EM wave launcher according toanother embodiment;

FIG. 12B presents a schematic cross-sectional view of a portion of theEM wave launcher depicted in FIG. 12A;

FIG. 13A provides a bottom view of an EM wave launcher according to yetanother embodiment;

FIG. 13B presents a schematic cross-sectional view of a portion of an EMwave launcher depicted in FIG. 13A; and

FIGS. 14A and 14B provide exemplary data for a SWP source.

DETAILED DESCRIPTION

A SWP source is disclosed in various embodiments. However, one skilledin the relevant art will recognize that the various embodiments may bepracticed without one or more of the specific details, or with otherreplacement and/or additional methods, materials, or components. Inother instances, well-known structures, materials, or operations are notshown or described in detail to avoid obscuring aspects of variousembodiments of the invention.

Similarly, for purposes of explanation, specific numbers, materials, andconfigurations are set forth in order to provide a thoroughunderstanding of the invention. Nevertheless, the invention may bepracticed without specific details. Furthermore, it is understood thatthe various embodiments shown in the figures are illustrativerepresentations and are not necessarily drawn to scale.

Reference throughout this specification to “one embodiment” or “anembodiment” or variation thereof means that a particular feature,structure, material, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention, butdoes not denote that they are present in every embodiment. Thus, theappearances of the phrases such as “in one embodiment” or “in anembodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the invention.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Nonetheless, it should be appreciated that contained within thedescription are features that, notwithstanding the inventive nature ofthe general concepts being explained, are also of an inventive nature.

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIG. 1Aillustrates a plasma processing system 100 according to an embodiment.The plasma processing system 100 may comprise a dry plasma etchingsystem or a plasma enhanced deposition system.

The plasma processing system 100 comprises a processing chamber 110configured to define a process space 115. The processing chamber 110comprises a substrate holder 120 configured to support a substrate 125.Therein, the substrate 125 is exposed to plasma or process chemistry inprocess space 115. Furthermore, the plasma processing system 100comprises a plasma source 130 coupled to the processing chamber 110, andconfigured to form plasma in the process space 115. The plasma source130 comprises a surface wave plasma (SWP) source, such as a radial lineslot antenna (RLSA), to be discussed below.

As seen in FIG. 1A, the plasma processing system 100 comprises a gassupply system 135 coupled to the processing chamber 110 and configuredto introduce a process gas to process space 115. During dry plasmaetching, the process gas may comprise an etchant, a passivant, or aninert gas, or a combination of two or more thereof. For example, whenplasma etching a dielectric film such as silicon oxide (SiO_(x)) orsilicon nitride (Si_(x)N_(y)), the plasma etch gas composition generallyincludes a fluorocarbon-based chemistry (C_(R)F_(s)) such as at leastone of C₄F₈, C₅F₈, C₃F₆, C₄F₆, CF₄, etc., and/or may include afluorohydrocarbon-based chemistry (C_(x)H_(y)F_(z)) such as at least oneof CHF₃, CH₂F₂, etc., and can have at least one of an inert gas, oxygen,CO or CO₂. Additionally, for example, when etching polycrystallinesilicon (polysilicon), the plasma etch gas composition generallyincludes a halogen-containing gas such as HBr, Cl₂, NF₃, or SF6 or acombination of two or more thereof, and may includefluorohydrocarbon-based chemistry (C_(x)H_(y)F_(z)) such as at least oneof CHF₃, CH₂F₂, etc., and at least one of an inert gas, oxygen, CO orCO₂, or two or more thereof. During plasma enhanced deposition, theprocess gas may comprise a film forming precursor, a reduction gas, oran inert gas, or a combination of two or more thereof.

Furthermore, the plasma processing system 100 includes a pumping system180 coupled to the processing chamber 110, and configured to evacuatethe processing chamber 110, as well as control the pressure within theprocessing chamber 110. Optionally, the plasma processing system 100further includes a control system 190 coupled to the processing chamber110, the substrate holder 120, the plasma source 130, the gas supplysystem 135, and the pumping system 180. The control system 190 can beconfigured to execute a process recipe for performing at least one of anetch process and a deposition process in the plasma processing system100.

Referring still to FIG. 1A, the plasma processing system 100 may beconfigured to process 200 mm substrates, 300 mm substrates, orlarger-sized substrates. In fact, it is contemplated that the plasmaprocessing system may be configured to process substrates, wafers, orLCDs regardless of their size, as would be appreciated by those skilledin the art. Therefore, while aspects of the invention will be describedin connection with the processing of a semiconductor substrate, theinvention is not limited solely thereto.

As described above, the processing chamber 110 is configured tofacilitate the generation of plasma in process space 115, and generateprocess chemistry in process space 115 adjacent a surface of thesubstrate 125. For example, in an etch process, the process gas caninclude molecular constituents that when dissociated are reactive withthe material being etched on the substrate surface. Once plasma isformed in the process space 115, heated electrons can collide withmolecules in the process gas causing dissociation and the formation ofreactive radicals for performing an etch process, for example.

Referring now to FIG. 1B, a plasma processing system 100′ is presentedaccording to another embodiment. Plasma processing system 100′ comprisesa processing chamber 110′ having an upper chamber portion 112 (i.e., afirst chamber portion) configured to define a plasma space 116, and alower chamber portion 114 (i.e., a second chamber portion) configured todefine a process space 118. In the lower chamber portion 114, theprocessing chamber 110′ comprises a substrate holder 120 configured tosupport a substrate 125. Therein, the substrate 125 is exposed toprocess chemistry in process space 118. Furthermore, the plasmaprocessing system 100′ comprises a plasma source 130 coupled to theupper chamber portion 112, and configured to form plasma in the plasmaspace 116. The plasma source 130 comprises a surface wave plasma (SWP)source, such as a radial line slot antenna (RLSA), to be discussedbelow.

As seen in FIG. 1B, the plasma processing system 100′ comprises a gasinjection grid 140 coupled to the upper chamber portion 112 and thelower chamber portion 114, and located between the plasma space 116 andthe process space 118. While FIG. 1B shows the gas injection grid 140positioned centrally to divide the processing chamber such that theupper chamber portion 112 is substantially equal in size to the lowerchamber portion 114, the invention is not limited to this configuration.For example, the gas injection grid 140 can be located within 200 mmfrom the upper surface of the substrate 125 and, desirably, the gasinjection grid 140 is placed within a range of approximately 10 mm toapproximately 150 mm from the upper surface of the substrate 125.

In the embodiment of FIG. 1B, the gas injection grid 140 separating theupper chamber portion 112 from the lower chamber portion 114 isconfigured to introduce a first gas 142 to the plasma space 116 forforming plasma and to introduce a second gas 144 to the process space118 for forming process chemistry. However, it is not necessary for thefirst and second gases 142, 144 to be introduced to their respectivechamber portions by way of the gas injection grid 140. For example, theplasma source 130 may be configured to supply the first gas 142 to theplasma space 116. More generally, the gas injection grid 140 may notsupply gas to the processing chamber 110′, or it may supply one or bothof the first and second gases 142, 144.

In embodiment of FIG. 1B, a first gas supply system 150 is coupled tothe gas injection grid 140, and it is configured to supply the first gas142. Moreover, a second gas supply system 160 is coupled to the gasinjection grid 140, and it is configured to supply the second gas 144.The temperature of the gas injection grid 140 can be controlled using atemperature control system 170, and the electric potential of the gasinjection grid 140 can be controlled using an electric bias controlsystem 175.

Furthermore, the plasma processing system 100′ includes a pumping system180 coupled to the processing chamber 110, and configured to evacuatethe processing chamber 110′, as well as control the pressure within theprocessing chamber 110′. Optionally, the plasma processing system 100′further includes a control system 190 coupled to the processing chamber110′, the substrate holder 120, the plasma source 130, the gas injectiongrid 140, the first gas supply system 150, the second gas supply system160, the temperature control system 170, the electric bias controlsystem 175, and the pumping system 180. The control system 190 can beconfigured to execute a process recipe for performing at least one of anetch process, and a deposition process in the plasma processing system100′.

Referring still to FIG. 1B, the plasma processing system 100′ may beconfigured to process 200 mm substrates, 300 mm substrates, orlarger-sized substrates. In fact, it is contemplated that the plasmaprocessing system may be configured to process substrates, wafers, orLCDs regardless of their size, as would be appreciated by those skilledin the art. Therefore, while aspects of the invention will be describedin connection with the processing of a semiconductor substrate, theinvention is not limited solely thereto.

As described above, the processing chamber 110′ is configured tofacilitate the generation of plasma in plasma space 116, and generateprocess chemistry in process space 118 adjacent a surface of thesubstrate 125. The first gas 142, which is introduced to the plasmaspace 116, comprises a plasma forming gas, or an ionizable gas ormixture of gases. The first gas 142 can include an inert gas, such as aNoble gas. The second gas 144, which is introduced to the process space118, comprises a process gas or mixture of process gases. For example,in an etch process, the process gas can include molecular constituentsthat when dissociated are reactive with the material being etched on thesubstrate surface. Once plasma is formed in the plasma space 116, someof the plasma can diffuse into the process space 118 through the gasinjection grid 140. The heated electrons having diffused into theprocess space 118, can collide with molecules in the process gas causingdissociation and the formation of reactive radicals for performing anetch process, for example.

Separate plasma and process spaces such as that shown in exemplaryplasma processing system 100′ of FIG. 1B may provide improved processcontrol over conventional plasma processing systems. Specifically, theuse of a gas injection grid 140, as described above, can, for example,affect the formation of dense, low (to moderate) temperature (i.e.,electron temperature T_(e)) plasma in the plasma space 116, whileproducing a less dense, lower temperature plasma in the process space118. In doing so, the split injection scheme for the first and secondgases can affect a further reduction in the dissociation of themolecular composition in the second gas that is utilized for forming theprocess chemistry, which provides greater control over the process atthe substrate surface.

Additionally, the configuration of exemplary plasma processing system100′ shown in FIG. 1B can reduce damage to chamber components such asthe plasma source 130, by preventing process gases from entering theplasma space 116. For example, as an inert gas (i.e., first gas 142),such as argon (Ar), is introduced to the plasma space 116, plasma isformed and neutral Ar atoms are heated. The heated Ar neutral atomsdiffuse downwards through the gas injection grid 140, and enter thecooler process space proximate the substrate 125 (e.g., region of lowertemperature plasma). This diffusion of Ar neutral gas creates a gas flowinto the process space 118 that can reduce or eliminate back-diffusionof the molecular composition in the process gas (i.e., second gas 144).

Still further, the configuration of exemplary plasma processing system100′ shown in FIG. 1B may further reduce substrate damage caused by ionand electron interaction with the substrate 125. In particular, thediffusion of electrons and ions through the gas injection grid 140 intothe process space 118 provides fewer electrons and ions in this spacerelative to the processing system 100 described in FIG. 1A above.Moreover, many of these electrons and ions give up their energy to thedissociation of the process gas. Thus, fewer electrons and ions areavailable to interact with the substrate 125 and cause damage theretowhich is particularly important for low temperature processes becausedamage to the substrate 125 may not be annealed by the required processtemperature.

Referring now to FIG. 2, a schematic representation of a SWP source 230is provided according to an embodiment. The SWP source 230 comprises anelectromagnetic (EM) wave launcher 232 configured to couple EM energy ina desired EM wave mode to a plasma by generating a surface wave on aplasma surface 260 of the EM wave launcher 232 adjacent plasma.Furthermore, the SWP source 230 comprises a power coupling system 290coupled to the EM wave launcher 232, and configured to provide the EMenergy to the EM wave launcher 232 for forming the plasma.

The EM wave launcher 232 includes a microwave launcher configured toradiate microwave power into process space 115 (see FIG. 1A) or plasmaspace 116 (see FIG. 1B). The EM wave launcher 232 is coupled to thepower coupling system 290 via coaxial feed 238 through which microwaveenergy is transferred. The power coupling system 290 includes amicrowave source 292, such as a 2.45 GHz microwave power source.Microwave energy generated by the microwave source 292 is guided througha waveguide 294 to an isolator 296 for absorbing microwave energyreflected back to the microwave source 292. Thereafter, the microwaveenergy is converted to a coaxial TEM (transverse electromagnetic) modevia a coaxial converter 298. A tuner may be employed for impedancematching, and improved power transfer. The microwave energy is coupledto the EM wave launcher 232 via the coaxial feed 238, wherein anothermode change occurs from the TEM mode in the coaxial feed 238 to a TM(transverse magnetic) mode. Additional details regarding the design ofthe coaxial feed 238 and the EM wave launcher 232 can be found in U.S.Pat. No. 5,024,716, entitled “Plasma processing apparatus for etching,ashing, and film-formation”; the content of which is herein incorporatedby reference in its entirety.

Referring now to FIGS. 3 and 4, a schematic cross-sectional view and abottom view, respectively, of EM wave launcher 232 are providedaccording to an embodiment. The EM wave launcher 232 comprises thecoaxial feed 238 having an inner conductor 240, an outer conductor 242,and insulator 241, and a slot antenna 246 having a plurality of slots248 coupled between the inner conductor 240 and the outer conductor 242as shown in FIG. 3. The plurality of slots 248 permits the coupling ofEM energy from a first region above the slot antenna 246 to a secondregion below the slot antenna 246. The EM wave launcher 232 may furthercomprise a slow wave plate 244, and a resonator plate 250.

The number, geometry, size, and distribution of the slots 248 are allfactors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna 246 may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIG. 3, the EM wave launcher 232 may comprise a fluidchannel 256 that is configured to flow a temperature control fluid fortemperature control of the EM wave launcher 232. Although not shown, theEM wave launcher 232 may further be configured to introduce a processgas through the plasma surface 260 to the plasma.

Referring still to FIG. 3, the EM wave launcher 232 may be coupled to anupper chamber portion of a plasma processing system, wherein a vacuumseal can be formed between an upper chamber wall 252 and the EM wavelauncher 232 using a sealing device 254. The sealing device 254 caninclude an elastomer O-ring; however, other known sealing mechanisms maybe used.

In general, the inner conductor 240 and the outer conductor 242 of thecoaxial feed 238 comprise a conductive material, such as a metal, whilethe slow wave plate 244 and the resonator plate 250 comprise adielectric material. In the latter, the slow wave plate 244 and theresonator plate 250 preferably comprise the same material; however,different materials may be used. The material selected for fabricationof the slow wave plate 244 and the resonator plate 250 is chosen toreduce the wavelength of the propagating electromagnetic (EM) waverelative to the corresponding free-space wavelength, and the dimensionsof the slow wave plate 244 and the resonator plate 250 are chosen toensure the formation of a standing wave effective for radiating EMenergy into process space 115 (see FIG. 1A) or plasma space 116 (seeFIG. 1B).

The slow wave plate 244 and the resonator plate 250 can be fabricatedfrom a dielectric material, including silicon-containing materials suchas quartz (silicon dioxide), or a high dielectric constant (high-k)materials. For example, the high-k material may possess a dielectricconstant greater than a value of 4. In particular, when the plasmaprocessing system is utilized for etch process applications, quartz isoften chosen for compatibility with the etch process.

For example, the high-k material can include intrinsic crystal silicon,alumina ceramic, aluminum nitride, and sapphire. However, other high-kmaterials may be used. Moreover, a particular high-k material may beselected in accordance with the parameters of a particular process. Forexample, when the resonator plate 250 is fabricated from intrinsiccrystal silicon, the plasma frequency exceeds 2.45 GHz at a temperatureof 45 degrees C. Therefore, intrinsic crystal silicon is appropriate forlow temperature processes (i.e., less than 45 degrees C.). For highertemperature processes, the resonator plate 250 can be fabricated fromalumina (Al₂O₃), or sapphire.

The inventors have observed that plasma uniformity and plasma stabilityremain as challenges for the practical implementation of a SWP source asdescribed above. In the latter, the standing wave at the resonatorplate-plasma interface, i.e., at the plasma surface 260, may be prone tomode jumps as plasma parameters shift.

As shown in FIGS. 3 and 4, the EM wave launcher 232 is fabricated with afirst recess configuration 262 formed in the plasma surface 260 and asecond recess configuration 264 formed in the plasma surface 260according to one embodiment.

The first recess configuration 262 may comprise a first plurality ofrecesses. Each recess in the first recess configuration 262 may comprisea unique indentation or dimple formed within the plasma surface 260. Forexample, a recess in the first recess configuration 262 may comprise acylindrical geometry, a conical geometry, a frusto-conical geometry, aspherical geometry, an aspherical geometry, a rectangular geometry, apyramidal geometry, or any arbitrary shape. The first recessdistribution 262 may comprise recesses characterized by a first size(e.g., latitudinal dimension (or width), and/or longitudinal dimension(or depth)).

The second recess configuration 264 may comprise a plurality ofrecesses. Each recess in the second recess configuration 264 maycomprise a unique indentation or dimple formed within the plasma surface260. For example, a recess in the second recess configuration 264 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 264 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the recesses in the firstrecess configuration 262 may or may not be the same as the second sizeof the recesses in the second recess configuration 264. For instance,the second size may be smaller than the first size.

As shown in FIGS. 3 and 4, the resonator plate 250 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 260 on resonator plate 250 comprises a planar surface266 within which the first recess configuration 262 and the secondrecess configuration 264 are formed. Alternatively, the resonator plate250 comprises an arbitrary geometry. Therein, the plasma surface 260 maycomprise a non-planar surface within which the first recessconfiguration and the second recess configuration are formed (notshown). For example, the non-planar surface may be concave, or convex,or a combination thereof.

The propagation of EM energy in the resonator plate 250 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 250. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 262 may comprise a firstplurality of cylindrical recesses, wherein each of the first pluralityof cylindrical recesses is characterized by a first depth and a firstdiameter. As shown in FIG. 4, the first recess configuration 262 islocated near an outer region of the plasma surface 260.

The first diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first depth may be aninteger number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first diameter may be abouthalf the effective wavelength (λ/2), and the first difference betweenthe plate thickness and the first depth may be about half the effectivewavelength (λ/2) or about quarter the effective wavelength (λ/4).Additionally, for instance, the plate thickness may be about half theeffective wavelength (λ/2) or greater than half the effective wavelength(>λ/2).

Alternatively, the first diameter may range from about 25 mm to about 35mm, and the first difference between the plate thickness and the firstdepth may range from about 10 mm to about 35 mm. Alternatively yet, thefirst diameter may range from about 30 mm to about 35 mm, and the firstdifference may range from about 10 mm to about 20 mm. Alternatively yet,the first diameter and/or first depth may be a fraction of the platethickness.

In the first recess configuration 262, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the plasma surface 260. For example, thesurface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 264 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 4, the second recess configuration 264is located near an inner region of the plasma surface 260.

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2), and the second difference betweenthe plate thickness and the second depth may be about half the effectivewavelength (λ/2) or about quarter the effective wavelength (λ/4).Additionally, for instance, the plate thickness may be about half theeffective wavelength (λ/2) or greater than half the effective wavelength(>λ/2).

Alternatively, the second diameter may range from about 25 mm to about35 mm, and the second difference between the plate thickness and thesecond depth may range from about 10 mm to about 35 mm. Alternativelyyet, the second diameter may range from about 30 mm to about 35 mm, andthe second difference may range from about 10 mm to about 20 mm.Alternatively yet, the second diameter and/or second depth may be afraction of the plate thickness.

In the second recess configuration 264, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the plasma surface 260. For example, thesurface radius may range from about 1 mm to about 3 mm.

Referring again to FIG. 4, a bottom view of the EM wave launcher 232depicted in FIG. 3 is provided. The plurality of slots 248 in slotantenna 246 are illustrated as if one can see through resonator plate250 to the slot antenna 246. As shown in FIG. 4, the plurality of slots248 may be arranged in pairs, wherein each of the pair of slotscomprises a first slot oriented orthogonal to a second slot. However,the orientation of slots in the plurality of slots 248 may be arbitrary.For example, the orientation of slots in the plurality of slots 248 maybe according to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 262 is substantially aligned with a firstarrangement of slots in the plurality of slots 248. Therein, at leastone recess of the first recess configuration 262 is aligned with one ormore of the plurality of slots 248. The second recess configuration 264is either partly aligned with a second arrangement of slots in theplurality of slots 248 or not aligned with the second arrangement ofslots in the plurality of slots 248. As shown in FIG. 4, the secondrecess configuration 264 is not aligned with the second arrangement ofslots in the plurality of slots 248.

As a consequence, the inventors have observed that the first recessconfiguration 262 dominate plasma generation, and exhibit a relatively“full bright” glow across a range of power coupled to the EM wavelauncher 232 and a range of pressure in the space where plasma is formedadjacent the plasma surface 260. Further, the inventors have observedthat the second recess configuration 264 variably contribute to plasmageneration, and exhibit a variation from a relatively “dim” glow to a“bright” glow depending on the power and/or pressure. The regionsadjacent the planar surface 266 receive less power and, generally,remain relatively “dark” except at relatively high power.

Moreover, the inventors have observed that plasma formed in the firstrecess configuration 262 (i.e., aligned with the plurality of slots 248)is stable at low power. Plasma is formed via ionization proximate these(larger) dimples, and flows from the recesses of the first recessconfiguration 262 to recesses of the second recess configuration 264(i.e., not aligned/partly aligned with the plurality of slots 248). As aresult, plasma formed proximate these recesses of the first recessconfiguration 262 is stable over a wide range of power and pressure, asthe recesses of the second recess configuration 264 receive an“overflow” of plasma from the recesses of the first recess configuration262 and compensate for fluctuations in the plasma generation proximatethe recesses of the first recess configuration 262.

For improved control of plasma uniformity, the regions adjacent theplanar surface 266 should remain relatively “dark” so that the risk fordevelopment of a mode-pattern is reduced. Therefore, as illustrated inFIG. 4, the optimal placement of the first recess configuration 262 andthe second recess configuration 264 may be such that a relatively largenumber of recesses (of the first recess configuration 262), aligned withthe plurality of slots 248 in slot antenna 246, and a relatively largenumber of recesses (of the second recess configuration 264), not alignedwith the plurality of slots 248, are collectively arranged spatially forplasma uniformity, for example. Although, the arrangement of recessesmay be chosen to achieve plasma uniformity, it may also be desirable toachieve a non-uniform plasma that cooperates with other processparameters to achieve a uniform process at a surface of a substratebeing processed by the plasma.

Referring now to FIGS. 5A and 5B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 332 are providedaccording to another embodiment. The EM wave launcher 332 comprises aresonator plate 350 with plasma surface 360. The EM wave launcher 332further comprises a slot antenna having a first plurality of slots 348and a second plurality of slots 349. The first plurality of slots 348and the second plurality of slots 349 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 350 is located.

The number, geometry, size, and distribution of the slots 348, 349 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 5A and 5B, the EM wave launcher 332 is fabricated witha first recess configuration 362 formed in the plasma surface 360 and asecond recess configuration 364 formed in the plasma surface 360according to one embodiment.

The first recess configuration 362 may comprise a first plurality ofrecesses. Each recess in the first recess configuration 362 may comprisea unique indentation or dimple formed within the plasma surface 360. Forexample, a recess in the first recess configuration 362 may comprise acylindrical geometry, a conical geometry, a frusto-conical geometry, aspherical geometry, an aspherical geometry, a rectangular geometry, apyramidal geometry, or any arbitrary shape. The first recessdistribution 362 may comprise recesses characterized by a first size(e.g., latitudinal dimension (or width), and/or longitudinal dimension(or depth)).

The second recess configuration 364 may comprise a plurality ofrecesses. Each recess in the second recess configuration 364 maycomprise a unique indentation or dimple formed within the plasma surface360. For example, a recess in the second recess configuration 364 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 364 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the recesses in the firstrecess configuration 362 may or may not be the same as the second sizeof the recesses in the second recess configuration 364. For instance,the second size may be smaller than the first size.

As shown in FIGS. 5A and 5B, the resonator plate 350 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 360 on resonator plate 350 comprises a planar surface366 within which the first recess configuration 362 and the secondrecess configuration 364 are formed. Alternatively, the resonator plate350 comprises an arbitrary geometry. Therein, the plasma surface 360 maycomprise a non-planar surface 366 within which the first recessconfiguration 362 and the second recess configuration 364 are formed(not shown). For example, the non-planar surface may be concave, orconvex, or a combination thereof.

The propagation of EM energy in the resonator plate 350 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 350. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about a half wavelength thick (λ/2)or greater than about half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 362 may comprise a firstplurality of cylindrical recesses, wherein each of the first pluralityof cylindrical recesses is characterized by a first depth and a firstdiameter. As shown in FIG. 5A, the first recess configuration 362 islocated near an outer region of the plasma surface 360.

The first diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first depth may be aninteger number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first diameter may be abouthalf the effective wavelength (λ/2), and the first difference betweenthe plate thickness and the first depth may be about half the effectivewavelength (λ/2) or about quarter the effective wavelength (λ/4).Additionally, for instance, the plate thickness may be about half theeffective wavelength (λ/2) or greater than half the effective wavelength(>λ/2).

Alternatively, the first diameter may range from about 25 mm to about 35mm, and the first difference between the plate thickness and the firstdepth may range from about 10 mm to about 35 mm. Alternatively yet, thefirst diameter may range from about 30 mm to about 35 mm, and the firstdifference may range from about 10 mm to about 20 mm. Alternatively yet,the first diameter and/or first depth may be a fraction of the platethickness.

In the first recess configuration 362, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the plasma surface 360. For example, thesurface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 364 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 5A, the second recess configuration364 is located near an inner region of the plasma surface 360.

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2), and the second difference betweenthe plate thickness and the second depth may be about half the effectivewavelength (λ/2) or about quarter the effective wavelength (λ/4).Additionally, for instance, the plate thickness may be about half theeffective wavelength (λ/2) or greater than half the effective wavelength(>λ/2).

Alternatively, the second diameter may range from about 25 mm to about35 mm, and the second difference between the plate thickness and thesecond depth may range from about 10 mm to about 35 mm. Alternativelyyet, the second diameter may range from about 30 mm to about 35 mm, andthe second difference may range from about 10 mm to about 20 mm.Alternatively yet, the second diameter and/or the second depth may be afraction of the plate thickness.

In the second recess configuration 364, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the plasma surface 360. For example, thesurface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 348 and the second plurality of slots 349in the slot antenna are illustrated as if one can see through resonatorplate 350 to the slot antenna. As shown in FIG. 5A, the first pluralityof slots 348 and the second plurality of slots 349 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 348 and the second plurality of slots 349 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 348 and the second plurality of slots 349 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 362 is substantially aligned with thefirst plurality of slots 348. Therein, at least one recess of the firstrecess configuration 362 is aligned with one or more of the firstplurality of slots 348. The second recess configuration 364 is eitherpartly aligned with the second plurality of slots 349 or not alignedwith the second plurality of slots 349. As shown in FIG. 5A, the secondrecess configuration 364 is partly aligned with the second plurality ofslots 349, wherein the second recess configuration 364 possesses apartially direct overlap with a slot (e.g., a fraction of a slot is indirect view of a recess).

Referring now to FIGS. 6A and 6B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 432 are providedaccording to another embodiment. The EM wave launcher 432 comprises aresonator plate 450 with plasma surface 460. The EM wave launcher 432further comprises a slot antenna having a first plurality of slots 448and a second plurality of slots 449. The first plurality of slots 448and the second plurality of slots 449 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 450 is located.

The number, geometry, size, and distribution of the slots 448, 449 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 6A and 6B, the EM wave launcher 432 is fabricated witha first recess configuration 462 formed in the plasma surface 460 and asecond recess configuration 464 formed in the plasma surface 460according to one embodiment.

The first recess configuration 462 may comprise a shelf. The shelf inthe first recess configuration 462 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 462 may comprise a shelf characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 464 may comprise a plurality ofrecesses. Each recess in the second recess configuration 464 maycomprise a unique indentation or dimple formed within the plasma surface460. For example, a recess in the second recess configuration 464 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 464 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the shelf in the first recessconfiguration 462 may or may not be the same as the second size of therecesses in the second recess configuration 464. For instance, thesecond size may be smaller than the first size.

As shown in FIGS. 6A and 6B, the resonator plate 450 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 460 on resonator plate 450 comprises a planar surface466 within which the first recess configuration 462 and the secondrecess configuration 464 are formed. Alternatively, the resonator plate450 comprises an arbitrary geometry. Therein, the plasma surface 460 maycomprise a non-planar surface within which the first recessconfiguration and the second recess configuration are formed (notshown). For example, the non-planar surface may be concave, or convex,or a combination thereof.

The propagation of EM energy in the resonator plate 450 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 450. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 462 may comprise anannular shelf, wherein the annular shelf is characterized by a firstshelf depth and a first shelf width (or a first inner shelf radius and afirst outer shelf radius). As shown in FIG. 6A, the first recessconfiguration 462 is located a peripheral edge of the plasma surface460.

The first shelf width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first shelf depth may bean integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first shelf width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first shelf depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first shelf width may range from about 25 mm to about75 mm, and the first difference between the plate thickness and thefirst shelf depth may range from about 10 mm to about 35 mm.Alternatively yet, the first shelf width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first shelf width and/or the firstshelf depth may be a fraction of the plate thickness.

In the first recess configuration 462, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular shelfrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the bottom of the recess. Additionally, in anannular shelf recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 460. Forexample, the surface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 464 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 6A, the second recess configuration464 is located near an inner region of the plasma surface 460. Althoughnot shown, the second recess configuration 464 may comprise a secondshelf, such as a second annular shelf that is characterized by a secondshelf depth and a second shelf width (or second inner shelf radius andsecond outer shelf radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 464, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 460. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 448 and the second plurality of slots 449in the slot antenna are illustrated as if one can see through resonatorplate 450 to the slot antenna. As shown in FIG. 6A, the first pluralityof slots 448 and the second plurality of slots 449 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 448 and the second plurality of slots 449 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 448 and the second plurality of slots 449 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 462 is substantially aligned with thefirst plurality of slots 448. The second recess configuration 464 iseither partly aligned with the second plurality of slots 449 or notaligned with the second plurality of slots 449. As shown in FIG. 6A, thesecond recess configuration 464 is partly aligned with the secondplurality of slots 449, wherein the second recess configuration 464possesses a partial direct overlap with a slot.

Referring now to FIGS. 7A and 7B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 532 are providedaccording to another embodiment. The EM wave launcher 532 comprises aresonator plate 550 with plasma surface 560. The EM wave launcher 532further comprises a slot antenna having a first plurality of slots 548and a second plurality of slots 549. The first plurality of slots 548and the second plurality of slots 549 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 550 is located.

The number, geometry, size, and distribution of the slots 548, 549 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 7A and 7B, the EM wave launcher 532 is fabricated witha first recess configuration 562 formed in the plasma surface 560 and asecond recess configuration 564 formed in the plasma surface 560according to one embodiment.

The first recess configuration 562 may comprise a shelf. The shelf inthe first recess configuration 562 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 562 may comprise a shelf characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 564 may comprise a plurality ofrecesses. Each recess in the second recess configuration 564 maycomprise a unique indentation or dimple formed within the plasma surface560. For example, a recess in the second recess configuration 564 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 564 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the shelf in the first recessconfiguration 562 may or may not be the same as the second size of therecesses in the second recess configuration 564. For instance, thesecond size may be smaller than the first size.

As shown in FIGS. 7A and 7B, the resonator plate 550 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 560 on resonator plate 550 comprises a planar surface566 within which the first recess configuration 562 and the secondrecess configuration 564 are formed. Alternatively, the resonator plate550 comprises an arbitrary geometry. Therein, the plasma surface 560 maycomprise a non-planar surface within which the first recessconfiguration and the second recess configuration are formed (notshown). For example, the non-planar surface may be concave, or convex,or a combination thereof.

The propagation of EM energy in the resonator plate 550 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 550. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 562 may comprise anannular shelf, wherein the annular shelf is characterized by a firstshelf depth and a first shelf width (or a first inner shelf radius andfirst outer shelf radius). As shown in FIG. 7A, the first recessconfiguration 562 is located a peripheral edge of the plasma surface560.

The first shelf width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first shelf depth may bean integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first shelf width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first shelf depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first shelf width may range from about 25 mm to about75 mm, and the first difference between the plate thickness and thefirst shelf depth may range from about 10 mm to about 35 mm.Alternatively yet, the first shelf width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first shelf width and/or the firstshelf depth may be a fraction of the plate thickness.

In the first recess configuration 562, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular shelfrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the bottom of the recess. Additionally, in anannular shelf recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 560. Forexample, the surface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 564 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 7A, the second recess configuration564 is located near an inner region of the plasma surface 560. Althoughnot shown, the second recess configuration 564 may comprise a secondshelf, such as a second annular shelf that is characterized by a secondshelf depth and a second shelf width (or second inner shelf radius andsecond outer shelf radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 564, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 560. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 548 and the second plurality of slots 549in the slot antenna are illustrated as if one can see through resonatorplate 550 to the slot antenna. As shown in FIG. 7A, the first pluralityof slots 548 and the second plurality of slots 549 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 548 and the second plurality of slots 549 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 548 and the second plurality of slots 549 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 562 is substantially aligned with thefirst plurality of slots 548. The second recess configuration 564 iseither aligned, partly aligned, or not aligned with the second pluralityof slots 549. As shown in FIG. 7A, the second recess configuration 564is substantially aligned with the second plurality of slots 549.

Referring now to FIGS. 8A and 8B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 632 are providedaccording to another embodiment. The EM wave launcher 632 comprises aresonator plate 650 with plasma surface 660. The EM wave launcher 632further comprises a slot antenna having a first plurality of slots 648and a second plurality of slots 649. The first plurality of slots 648and the second plurality of slots 649 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 650 is located.

The number, geometry, size, and distribution of the slots 648, 649 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 8A and 8B, the EM wave launcher 632 is fabricated witha first recess configuration 662 formed in the plasma surface 660 and asecond recess configuration 664 formed in the plasma surface 660according to one embodiment.

The first recess configuration 662 may comprise a shelf. The shelf inthe first recess configuration 662 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 662 may comprise a shelf characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 664 may comprise a plurality ofrecesses. Each recess in the second recess configuration 664 maycomprise a unique indentation or dimple formed within the plasma surface660. For example, a recess in the second recess configuration 664 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 664 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the shelf in the first recessconfiguration 662 may or may not be the same as the second size of therecesses in the second recess configuration 664. For instance, thesecond size may be smaller than the first size.

As shown in FIGS. 8A and 8B, the resonator plate 650 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 660 on resonator plate 650 comprises a planar surface666 within which the first recess configuration 662 and the secondrecess configuration 664 are formed. Alternatively, the resonator plate650 comprises an arbitrary geometry. Therein, the plasma surface 660 maycomprise a non-planar surface within which the first recessconfiguration and the second recess configuration are formed (notshown). For example, the non-planar surface may be concave, or convex,or a combination thereof.

The propagation of EM energy in the resonator plate 650 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 650. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 662 may comprise anannular shelf, wherein the annular shelf is characterized by a firstshelf depth and a first shelf width (or a first inner shelf radius andfirst outer shelf radius). As shown in FIG. 8A, the first recessconfiguration 662 is located a peripheral edge of the plasma surface660.

The first shelf width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first shelf depth may bean integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first shelf width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first shelf depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first shelf width may range from about 25 mm to about75 mm, and the first difference between the plate thickness and thefirst shelf depth may range from about 10 mm to about 35 mm.Alternatively yet, the first shelf width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first shelf width and/or the firstshelf depth may be a fraction of the plate thickness.

In the first recess configuration 662, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular shelfrecess, a surface radius may be disposed at the corner between thecylindrical sidewall and the bottom of the recess. Additionally, in anannular shelf recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 660. Forexample, the surface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 664 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 8A, the second recess configuration664 is located near an inner region of the plasma surface 660. Althoughnot shown, the second recess configuration 664 may comprise a secondshelf, such as a second annular shelf that is characterized by a secondshelf depth and a second shelf width (or second inner shelf radius andsecond outer shelf radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 664, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 660. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 648 and the second plurality of slots 649in the slot antenna are illustrated as if one can see through resonatorplate 650 to the slot antenna. As shown in FIG. 8A, the first pluralityof slots 648 and the second plurality of slots 649 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 648 and the second plurality of slots 649 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 648 and the second plurality of slots 649 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 662 is substantially aligned with thefirst plurality of slots 648. The second recess configuration 664 iseither partly aligned with the second plurality of slots 649 or notaligned with the second plurality of slots 649. As shown in FIG. 8A, thesecond recess configuration 664 is partly aligned with the secondplurality of slots 649, wherein the second recess configuration 664possesses no direct overlap with a slot.

Referring now to FIGS. 9A and 9B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 732 are providedaccording to another embodiment. The EM wave launcher 732 comprises aresonator plate 750 with plasma surface 760. The EM wave launcher 732further comprises a slot antenna having a first plurality of slots 748and a second plurality of slots 749. The first plurality of slots 748and the second plurality of slots 749 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 750 is located.

The number, geometry, size, and distribution of the slots 748, 749 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 9A and 9B, the EM wave launcher 732 is fabricated witha first recess configuration 762 formed in the plasma surface 760 and asecond recess configuration 764 formed in the plasma surface 760according to one embodiment. However, in another embodiment, the secondrecess configuration 764 is excluded. As shown in FIGS. 9C and 9D, an EMwave launcher 732′ is depicted having a plasma surface 760′ thatexcludes the second recess configuration 764.

The first recess configuration 762 may comprise a channel. The channelin the first recess configuration 762 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 762 may comprise a channel characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 764 may comprise a plurality ofrecesses. Each recess in the second recess configuration 764 maycomprise a unique indentation or dimple formed within the plasma surface760. For example, a recess in the second recess configuration 764 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 764 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the channel in the first recessconfiguration 762 may or may not be the same as the second size of therecesses in the second recess configuration 764. For instance, thesecond size may be smaller than the first size.

As shown in FIGS. 9A and 9B, the resonator plate 750 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 760 on resonator plate 750 comprises a planar surface766 within which the first recess configuration 762 and the secondrecess configuration 764 are formed. Alternatively, the resonator plate750 comprises an arbitrary geometry. Therein, the plasma surface 760 maycomprise a non-planar surface within which the first recessconfiguration and the second recess configuration are formed (notshown). For example, the non-planar surface may be concave, or convex,or a combination thereof.

The propagation of EM energy in the resonator plate 750 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 750. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 762 may comprise anannular channel, wherein the annular channel is characterized by a firstchannel depth and a first channel width (or a first inner channel radiusand first outer channel radius). As shown in FIG. 9A, the first recessconfiguration 762 is located a peripheral edge of the plasma surface760.

The first channel width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first channel depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first channel width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first channel depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first channel width may range from about 25 mm toabout 75 mm, and the first difference between the plate thickness andthe first channel depth may range from about 10 mm to about 35 mm.Alternatively yet, the first channel width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first channel width and/or the firstchannel depth may be a fraction of the plate thickness.

In the first recess configuration 762, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular channelrecess, a surface radius may be disposed at the corner between acylindrical sidewall and the bottom of the recess. Additionally, in anannular channel recess, a surface radius may be disposed at the cornerbetween a cylindrical sidewall and the plasma surface 760. For example,the surface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 764 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 9A, the second recess configuration764 is located near an inner region of the plasma surface 760. Althoughnot shown, the second recess configuration 764 may comprise a secondchannel, such as a second annular channel that is characterized by asecond channel depth and a second channel width (or second inner channelradius and second outer channel radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 764, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 760. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 748 and the second plurality of slots 749in the slot antenna are illustrated as if one can see through resonatorplate 750 to the slot antenna. As shown in FIG. 9A, the first pluralityof slots 748 and the second plurality of slots 749 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 748 and the second plurality of slots 749 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 748 and the second plurality of slots 749 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 762 is substantially aligned with thefirst plurality of slots 748. The second recess configuration 764 iseither partly aligned with the second plurality of slots 749 or notaligned with the second plurality of slots 749. As shown in FIG. 9A, thesecond recess configuration 764 is partially aligned with the secondplurality of slots 749, wherein the second recess configuration 764possesses a partial direct overlap with a slot.

As shown in FIG. 9E, a bottom view of EM wave launcher 732 is provided,wherein the slot antenna has been rotated relative to the resonatorplate 750. The original orientation of the slot antenna, including thefirst plurality of slots 748 and the second plurality of slots 749, isillustrated with solid lines. The rotated orientation of the slotantenna, including a first plurality of slots 748′ and a secondplurality of slots 749′, is illustrated with dashed lines (the firstplurality of slots 748′ are shown to be slightly mis-aligned with theoriginal arrangement of the first plurality of slots 748 forillustrative purposes). The orientation (i.e., rotation) of the slotantenna relative to the resonator plate 750, including the first recessconfiguration 762 and the second recess configuration 764, may bealtered in order to adjust the plasma uniformity and/or plasmastability. For example, in the original arrangement, the first pluralityof slots 748 aligns with the first recess configuration 762, and thesecond plurality of slots 749 aligns with the second recessconfiguration 764. Additionally, for example, in the rotatedarrangement, the first plurality of slots 748′ aligns with the firstrecess configuration 762′, and the second plurality of slots 749′ doesnot align with the second recess configuration 764.

Referring now to FIGS. 10A and 10B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 832 are providedaccording to another embodiment. The EM wave launcher 832 comprises aresonator plate 850 with plasma surface 860. The EM wave launcher 832further comprises a slot antenna having a first plurality of slots 848and a second plurality of slots 849. The first plurality of slots 848and the second plurality of slots 849 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 850 is located.

The number, geometry, size, and distribution of the slots 848, 849 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 10A and 10B, the EM wave launcher 832 is fabricatedwith a first recess configuration 862 formed in the plasma surface 860and a second recess configuration 864 formed in the plasma surface 860according to one embodiment.

The first recess configuration 862 may comprise a channel. The channelin the first recess configuration 862 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 862 may comprise a channel characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 864 may comprise a plurality ofrecesses. Each recess in the second recess configuration 864 maycomprise a unique indentation or dimple formed within the plasma surface860. For example, a recess in the second recess configuration 864 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 864 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the channel in the first recessconfiguration 862 may or may not be the same as the second size of therecesses in the second recess configuration 864. For instance, thesecond size may be smaller than the first size.

As shown in FIGS. 10A and 10B, the resonator plate 850 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 860 on resonator plate 850 comprises a planar surface866 within which the first recess configuration 862 and the secondrecess configuration 864 are formed. Alternatively, the resonator plate850 comprises an arbitrary geometry. Therein, the plasma surface 860 maycomprise a non-planar surface within which the first recessconfiguration and the second recess configuration are formed (notshown). For example, the non-planar surface may be concave, or convex,or a combination thereof.

The propagation of EM energy in the resonator plate 850 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 850. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 862 may comprise anannular channel, wherein the annular channel is characterized by a firstchannel depth and a first channel width (or a first inner channel radiusand first outer channel radius). As shown in FIG. 10A, the first recessconfiguration 862 is located a peripheral edge of the plasma surface860.

The first channel width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first channel depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first channel width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first channel depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first channel width may range from about 25 mm toabout 75 mm, and the first difference between the plate thickness andthe first channel depth may range from about 10 mm to about 35 mm.Alternatively yet, the first channel width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first channel width and/or the firstchannel depth may be a fraction of the plate thickness.

Additionally, the first recess configuration 862 may comprise a thirdplurality of cylindrical recesses 863 formed at a bottom of the firstannular channel, wherein each of the third plurality of cylindricalrecesses may be characterized by a third depth and a third diameter.Alternatively, the annular channel may be an annular shelf within whichthe third plurality of cylindrical recesses is formed at a bottom of theannular shelf. Alternatively yet, the first recess configuration 862 maycomprise a third channel formed at a bottom of the first annularchannel, wherein the third channel may be characterized by a thirdchannel depth and a third channel width.

The third diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a thirddifference between the plate thickness and the third depth may be aninteger number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the third diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a third difference between the plate thickness andthe third depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the third diameter may range from about 25 mm to about 75mm, and the third difference between the plate thickness and the thirddepth may range from about 10 mm to about 35 mm. Alternatively yet, thethird diameter may range from about 55 mm to about 65 mm, and the thirddifference may range from about 10 mm to about 20 mm. Alternatively yet,the third diameter width and/or the third depth may be a fraction of theplate thickness.

In the first recess configuration 862, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular channelrecess or cylindrical recess, a surface radius may be disposed at thecorner between a cylindrical sidewall and the bottom of the recess.Additionally, in an annular channel recess or cylindrical recess, asurface radius may be disposed at the corner between a cylindricalsidewall and the plasma surface 860. For example, the surface radius mayrange from about 1 mm to about 3 mm.

As another example, the second recess configuration 864 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 10A, the second recess configuration864 is located near an inner region of the plasma surface 860. Althoughnot shown, the second recess configuration 864 may comprise a secondchannel, such as a second annular channel that is characterized by asecond channel depth and a second channel width (or second inner channelradius and second outer channel radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 864, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 860. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 848 and the second plurality of slots 849in the slot antenna are illustrated as if one can see through resonatorplate 850 to the slot antenna. As shown in FIG. 10A, the first pluralityof slots 848 and the second plurality of slots 849 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 848 and the second plurality of slots 849 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 848 and the second plurality of slots 849 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 862 is substantially aligned with thefirst plurality of slots 848. The second recess configuration 864 iseither partly aligned with the second plurality of slots 849 or notaligned with the second plurality of slots 849. As shown in FIG. 10A,the second recess configuration 864 is partly aligned with the secondplurality of slots 849, wherein the second recess configuration 864possesses a partial direct overlap with a slot.

Referring now to FIGS. 11A and 11B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 932 are providedaccording to another embodiment. The EM wave launcher 932 comprises aresonator plate 950 with plasma surface 960. The EM wave launcher 932further comprises a slot antenna having a first plurality of slots 948and a second plurality of slots 949. The first plurality of slots 948and the second plurality of slots 949 permit the coupling of EM energyfrom a first region above the slot antenna to a second region below theslot antenna wherein the resonator plate 950 is located.

The number, geometry, size, and distribution of the slots 948, 949 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 11A and 11B, the EM wave launcher 932 is fabricatedwith a first recess configuration 962 formed in the plasma surface 960,a second recess configuration 964 formed in the plasma surface 960, anda third recess configuration 965 formed in the plasma surface 960according to one embodiment.

The first recess configuration 962 may comprise a channel. The channelin the first recess configuration 962 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 962 may comprise a channel characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 964 may comprise a plurality ofrecesses. Each recess in the second recess configuration 964 maycomprise a unique indentation or dimple formed within the plasma surface960. For example, a recess in the second recess configuration 964 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 964 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the channel in the first recessconfiguration 962 may or may not be the same as the second size of therecesses in the second recess configuration 964. For instance, thesecond size may be smaller than the first size.

The third recess configuration 965 may comprise a plurality of recesses.Each recess in the third recess configuration 965 may comprise a uniqueindentation or dimple formed within the plasma surface 960. For example,a recess in the third recess configuration 965 may comprise acylindrical geometry, a conical geometry, a frusto-conical geometry, aspherical geometry, an aspherical geometry, a rectangular geometry, apyramidal geometry, or any arbitrary shape. The third recessdistribution 965 may comprise recesses characterized by a third size(e.g., latitudinal dimension (or width), and/or longitudinal dimension(or depth)). The first size of the channel in the first recessconfiguration 962 may or may not be the same as the third size of therecesses in the third recess configuration 965. For instance, the thirdsize may be smaller than the first size and/or second size.

As shown in FIGS. 11A and 11B, the resonator plate 950 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 960 on resonator plate 950 comprises a planar surface966 within which the first recess configuration 962, the second recessconfiguration 964, and the third recess configuration 965 are formed.Alternatively, the resonator plate 950 comprises an arbitrary geometry.Therein, the plasma surface 960 may comprise a non-planar surface withinwhich the first recess configuration and the second recess configurationare formed (not shown). For example, the non-planar surface may beconcave, or convex, or a combination thereof.

The propagation of EM energy in the resonator plate 950 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 950. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 962 may comprise anannular channel, wherein the annular channel is characterized by a firstchannel depth and a first channel width (or a first inner channel radiusand first outer channel radius). As shown in FIG. 11A, the first recessconfiguration 962 is located a peripheral edge of the plasma surface960.

The first channel width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first channel depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first channel width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first channel depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first channel width may range from about 25 mm toabout 75 mm, and the first difference between the plate thickness andthe first channel depth may range from about 10 mm to about 35 mm.Alternatively yet, the first channel width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first channel width and/or the firstchannel depth may be a fraction of the plate thickness.

Additionally, the first recess configuration 962 may comprise a fourthplurality of cylindrical recesses 963 formed at a bottom of the firstannular channel, wherein each of the fourth plurality of cylindricalrecesses may be characterized by a fourth depth and a fourth diameter.Alternatively, the annular channel may be an annular shelf within whichthe fourth plurality of cylindrical recesses is formed at a bottom ofthe annular shelf. Alternatively yet, the first recess configuration 962may comprise a fourth channel formed at a bottom of the first annularchannel, wherein the fourth channel may be characterized by a fourthchannel depth and a fourth channel width.

The fourth diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, afourth difference between the plate thickness and the fourth depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the fourth diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a fourth difference between the plate thicknessand the fourth depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the fourth diameter may range from about 25 mm to about75 mm, and the fourth difference between the plate thickness and thefourth depth may range from about 10 mm to about 35 mm. Alternativelyyet, the fourth diameter may range from about 55 mm to about 65 mm, andthe fourth difference may range from about 10 mm to about 20 mm.Alternatively yet, the fourth diameter and/or the fourth depth may be afraction of the plate thickness.

In the first recess configuration 962, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular channelrecess or cylindrical recess, a surface radius may be disposed at thecorner between a cylindrical sidewall and the bottom of the recess.Additionally, in an annular channel recess or cylindrical recess, asurface radius may be disposed at the corner between a cylindricalsidewall and the plasma surface 960. For example, the surface radius mayrange from about 1 mm to about 3 mm.

As another example, the second recess configuration 964 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 11A, the second recess configuration964 is located near an inner region of the plasma surface 960. Althoughnot shown, the second recess configuration 964 may comprise a secondchannel, such as a second annular channel that is characterized by asecond channel depth and a second channel width (or second inner channelradius and second outer channel radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 964, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 960. Forexample, the surface radius may range from about 1 mm to about 3 mm.

As yet another example, the third recess configuration 965 may comprisea third plurality of cylindrical recesses, each of the third pluralityof cylindrical recesses being characterized by a third depth and a thirddiameter. As shown in FIG. 11A, the third recess configuration 965 islocated near an inner region of the plasma surface 960. Although notshown, the third recess configuration 965 may comprise a third channel,such as a third annular channel that is characterized by a third channeldepth and a third channel width (or third inner channel radius and thirdouter channel radius).

The third diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), ornon-integral fraction of the effective wavelength. Additionally, a thirddifference between the plate thickness and the third depth may be aninteger number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the third diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a third difference between the plate thickness andthe third depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the third diameter may range from about 25 mm(millimeters) to about 35 mm, and the third difference between the platethickness and the third depth may range from about 10 mm to about 35 mm.Alternatively yet, the third diameter may range from about 30 mm toabout 35 mm, and the third difference may range from about 10 mm toabout 20 mm. Alternatively yet, the third diameter and/or the thirddepth may be a fraction of the plate thickness.

In the third recess configuration 965, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 960. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 948 and the second plurality of slots 949in the slot antenna are illustrated as if one can see through resonatorplate 950 to the slot antenna. As shown in FIG. 11A, the first pluralityof slots 948 and the second plurality of slots 949 may be arranged inpairs, wherein each of the pair of slots comprises a first slot orientedorthogonal to a second slot. However, the orientation of slots in thefirst plurality of slots 948 and the second plurality of slots 949 maybe arbitrary. For example, the orientation of slots in the firstplurality of slots 948 and the second plurality of slots 949 may beaccording to a pre-determined pattern for plasma uniformity and/orplasma stability.

The first recess configuration 962 is substantially aligned with thefirst plurality of slots 948. The second recess configuration 964 iseither partly aligned with the second plurality of slots 949 or notaligned with the second plurality of slots 949. The third recessconfiguration 965 is not aligned with the first plurality of slots 948or the second plurality of slots 949. As shown in FIG. 11A, the secondrecess configuration 964 is partly aligned with the second plurality ofslots 949, wherein the second recess configuration 964 possesses nodirect overlap with a slot.

As shown in FIG. 11C, a bottom view of EM wave launcher 932 is provided,wherein the slot antenna has been rotated relative to the resonatorplate 950. The original orientation of the slot antenna, including thefirst plurality of slots 948 and the second plurality of slots 949, isillustrated with solid lines. The rotated orientation of the slotantenna, including a first plurality of slots 948′ and a secondplurality of slots 949′, is illustrated with dashed lines (the firstplurality of slots 948′ are shown to be slightly mis-aligned with theoriginal arrangement of the first plurality of slots 948 forillustrative purposes). The orientation (i.e., rotation) of the slotantenna relative to the resonator plate 950, including the first recessconfiguration 962, the second recess configuration 964, and the thirdrecess configuration 965, may be altered in order to adjust the plasmauniformity and/or plasma stability. For example, in the originalarrangement, the first plurality of slots 948 aligns with the firstrecess configuration 962, and the second plurality of slots 949 partlyaligns with the second recess configuration 964. Additionally, forexample, in the rotated arrangement, the first plurality of slots 948′aligns with the first recess configuration 962′, and the secondplurality of slots 949′ does not align with the second recessconfiguration 964.

Referring now to FIGS. 12A and 12B, a bottom view and a schematiccross-sectional view, respectively, of EM wave launcher 1032 areprovided according to another embodiment. The EM wave launcher 1032comprises a resonator plate 1050 with plasma surface 1060. The EM wavelauncher 1032 further comprises a slot antenna having a first pluralityof slots 1048 and a second plurality of slots 1049. The first pluralityof slots 1048 and the second plurality of slots 1049 permit the couplingof EM energy from a first region above the slot antenna to a secondregion below the slot antenna wherein the resonator plate 1050 islocated.

The number, geometry, size, and distribution of the slots 1048, 1049 areall factors that can contribute to the spatial uniformity of the plasmaformed in process space 115 (see FIG. 1A) or plasma space 116 (see FIG.1B). Thus, the design of the slot antenna may be used to control thespatial uniformity of the plasma in process space 115 (see FIG. 1A) orplasma space 116 (see FIG. 1B).

As shown in FIGS. 12A and 12B, the EM wave launcher 1032 is fabricatedwith a first recess configuration 1062 formed in the plasma surface1060, a second recess configuration 1064 formed in the plasma surface1060, and a third recess configuration 1065 formed in the plasma surface1060 according to one embodiment.

The first recess configuration 1062 may comprise a channel. The channelin the first recess configuration 1062 may comprise an arbitrarygeometry including, for example, a cylindrical geometry, a conicalgeometry, a frusto-conical geometry, a spherical geometry, an asphericalgeometry, a rectangular geometry, a pyramidal geometry, or any arbitraryshape. The first recess distribution 1062 may comprise a channelcharacterized by a first size (e.g., latitudinal dimension (or width),and/or longitudinal dimension (or depth)).

The second recess configuration 1064 may comprise a plurality ofrecesses. Each recess in the second recess configuration 1064 maycomprise a unique indentation or dimple formed within the plasma surface1060. For example, a recess in the second recess configuration 1064 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The secondrecess distribution 1064 may comprise recesses characterized by a secondsize (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the channel in the first recessconfiguration 1062 may or may not be the same as the second size of therecesses in the second recess configuration 1064. For instance, thesecond size may be smaller than the first size.

The third recess configuration 1065 may comprise a plurality ofrecesses. Each recess in the third recess configuration 1065 maycomprise a unique indentation or dimple formed within the plasma surface1060. For example, a recess in the third recess configuration 1065 maycomprise a cylindrical geometry, a conical geometry, a frusto-conicalgeometry, a spherical geometry, an aspherical geometry, a rectangulargeometry, a pyramidal geometry, or any arbitrary shape. The third recessdistribution 1065 may comprise recesses characterized by a third size(e.g., latitudinal dimension (or width), and/or longitudinal dimension(or depth)). The first size of the channel in the first recessconfiguration 1062 may or may not be the same as the third size of therecesses in the third recess configuration 1065. For instance, the thirdsize may be smaller than the first size and/or second size.

As shown in FIGS. 12A and 12B, the resonator plate 1050 comprises adielectric plate having a plate diameter and a plate thickness. Therein,the plasma surface 1060 on resonator plate 1050 comprises a planarsurface 1066 within which the first recess configuration 1062, thesecond recess configuration 1064, and the third recess configuration1065 are formed. Alternatively, the resonator plate 1050 comprises anarbitrary geometry. Therein, the plasma surface 1060 may comprise anon-planar surface within which the first recess configuration and thesecond recess configuration are formed (not shown). For example, thenon-planar surface may be concave, or convex, or a combination thereof.

The propagation of EM energy in the resonator plate 1050 may becharacterized by an effective wavelength (λ) for a given frequency of EMenergy and dielectric constant for the resonator plate 1050. The platethickness may be an integer number of quarter wavelengths (nλ/4, where nis an integer greater than zero) or an integer number of halfwavelengths (mλ/2, where m is an integer greater than zero). Forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).Alternatively, the plate thickness may be a non-integral fraction of theeffective wavelength (i.e., not an integral number of half or quarterwavelengths). Alternatively yet, the plate thickness may range fromabout 25 mm (millimeters) to about 45 mm.

As an example, the first recess configuration 1062 may comprise anannular channel, wherein the annular channel is characterized by a firstchannel depth and a first channel width (or a first inner channel radiusand first outer channel radius). As shown in FIG. 11A, the first recessconfiguration 1062 is located a peripheral edge of the plasma surface1060.

The first channel width may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a firstdifference between the plate thickness and the first channel depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the first channel width may beabout the effective wavelength (λ), and a first difference between theplate thickness and the first channel depth may be about half theeffective wavelength (λ/2) or about quarter the effective wavelength(λ/4). Additionally, for instance, the plate thickness may be about halfthe effective wavelength (λ/2) or greater than half the effectivewavelength (>λ/2).

Alternatively, the first channel width may range from about 25 mm toabout 75 mm, and the first difference between the plate thickness andthe first channel depth may range from about 10 mm to about 35 mm.Alternatively yet, the first channel width may range from about 55 mm toabout 65 mm, and the first difference may range from about 10 mm toabout 20 mm. Alternatively yet, the first channel width and/or the firstchannel depth may be a fraction of the plate thickness.

In the first recess configuration 1062, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In an annular channelrecess, a surface radius may be disposed at the corner between acylindrical sidewall and the bottom of the recess. Additionally, in anannular channel recess, a surface radius may be disposed at the cornerbetween a cylindrical sidewall and the plasma surface 960. For example,the surface radius may range from about 1 mm to about 3 mm.

As another example, the second recess configuration 1064 may comprise asecond plurality of cylindrical recesses, each of the second pluralityof cylindrical recesses being characterized by a second depth and asecond diameter. As shown in FIG. 12A, the second recess configuration1064 is located near an inner region of the plasma surface 1060.Although not shown, the second recess configuration 1064 may comprise asecond channel, such as a second annular channel that is characterizedby a second channel depth and a second channel width (or second innerchannel radius and second outer channel radius).

The second diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, asecond difference between the plate thickness and the second depth maybe an integer number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the second diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a second difference between the plate thicknessand the second depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the second diameter may range from about 25 mm(millimeters) to about 35 mm, and the second difference between theplate thickness and the second depth may range from about 10 mm to about35 mm. Alternatively yet, the second diameter may range from about 30 mmto about 35 mm, and the second difference may range from about 10 mm toabout 20 mm. Alternatively yet, the second diameter and/or the seconddepth may be a fraction of the plate thickness.

In the second recess configuration 1064, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 1060. Forexample, the surface radius may range from about 1 mm to about 3 mm.

As yet another example, the third recess configuration 1065 may comprisea third plurality of cylindrical recesses, each of the third pluralityof cylindrical recesses being characterized by a third depth and a thirddiameter. As shown in FIG. 12A, the third recess configuration 1065 islocated near an inner region of the plasma surface 1060. Although notshown, the third recess configuration 1065 may comprise a third channel,such as a third annular channel that is characterized by a third channeldepth and a third channel width (or third inner channel radius and thirdouter channel radius).

The third diameter may be an integer number of quarter wavelengths(nλ/4, where n is an integer greater than zero), or an integer number ofhalf wavelengths (mλ/2, where m is an integer greater than zero), or anon-integral fraction of the effective wavelength. Additionally, a thirddifference between the plate thickness and the third depth may be aninteger number of quarter wavelengths (nλ/4, where n is an integergreater than zero), or an integer number of half wavelengths (mλ/2,where m is an integer greater than zero), or a non-integral fraction ofthe effective wavelength. For instance, the third diameter may be abouthalf the effective wavelength (λ/2) or about quarter the effectivewavelength (λ/4), and a third difference between the plate thickness andthe third depth may be about half the effective wavelength (λ/2) orabout quarter the effective wavelength (λ/4). Additionally, forinstance, the plate thickness may be about half the effective wavelength(λ/2) or greater than half the effective wavelength (>λ/2).

Alternatively, the third diameter may range from about 25 mm(millimeters) to about 35 mm, and the third difference between the platethickness and the third depth may range from about 10 mm to about 35 mm.Alternatively yet, the third diameter may range from about 30 mm toabout 35 mm, and the third difference may range from about 10 mm toabout 20 mm. Alternatively yet, the third diameter and/or the thirddepth may be a fraction of the plate thickness.

In the third recess configuration 1065, chamfers, rounds and/or fillets(i.e., surface/corner radius or bevel) may be utilized to affect smoothsurface transitions between adjacent surfaces. In a cylindrical recess,a surface radius may be disposed at the corner between the cylindricalsidewall and the bottom of the recess. Additionally, in a cylindricalrecess, the recess, a surface radius may be disposed at the cornerbetween the cylindrical sidewall and the plasma surface 1060. Forexample, the surface radius may range from about 1 mm to about 3 mm.

The first plurality of slots 1048 and the second plurality of slots 1049in the slot antenna are illustrated as if one can see through resonatorplate 1050 to the slot antenna. As shown in FIG. 12A, the firstplurality of slots 1048 and the second plurality of slots 1049 may bearranged in pairs, wherein each of the pair of slots comprises a firstslot oriented orthogonal to a second slot. However, the orientation ofslots in the first plurality of slots 1048 and the second plurality ofslots 1049 may be arbitrary. For example, the orientation of slots inthe first plurality of slots 1048 and the second plurality of slots 1049may be according to a pre-determined pattern for plasma uniformityand/or plasma stability.

The first recess configuration 1062 is substantially aligned with thefirst plurality of slots 1048. The second recess configuration 1064 iseither partly aligned with the second plurality of slots 1049 or notaligned with the second plurality of slots 1049. The third recessconfiguration 1065 is not aligned with the first plurality of slots 1048or the second plurality of slots 1049. As shown in FIG. 12A, the secondrecess configuration 1064 is partly aligned with the second plurality ofslots 1049, wherein the second recess configuration 1064 possesses nodirect overlap with a slot.

Referring now to FIGS. 13A and 13B, a schematic cross-sectional view ofan EM wave launcher 1132 is provided according to yet anotherembodiment. The EM wave launcher comprises a resonator plate 1150 withplasma surface 1160. The EM wave launcher further comprises a slotantenna having a first plurality of slots 1148 and optionally a secondplurality of slots 1149. The first plurality of slots 1148 and thesecond plurality of slots 1149 permit the coupling of EM energy from afirst region above the slot antenna to a second region below the slotantenna wherein the resonator plate 1150 is located.

As shown in FIGS. 13A and 13B, the EM wave launcher 1132 is fabricatedwith a first recess configuration 1162 formed in the plasma surface 1160and a second recess configuration 1164 formed in the plasma surface 1160according to one embodiment.

The first recess configuration 1162 may comprise a channel having atrapezoidal or frusto-triangular cross-section. However, the channel inthe first recess configuration 1162 may comprise an arbitrary geometryincluding, for example, a cylindrical geometry, a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thefirst recess distribution 1162 may comprise a channel characterized by afirst size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)).

The second recess configuration 1164 may comprise a plurality ofrecesses. Each recess in the second recess configuration 1164 maycomprise a unique indentation or dimple formed within the plasma surface1160. For example, a recess in the second recess configuration 1164 maycomprise a cylindrical geometry (as shown), a conical geometry, afrusto-conical geometry, a spherical geometry, an aspherical geometry, arectangular geometry, a pyramidal geometry, or any arbitrary shape. Thesecond recess distribution 1164 may comprise recesses characterized by asecond size (e.g., latitudinal dimension (or width), and/or longitudinaldimension (or depth)). The first size of the channel in the first recessconfiguration 1162 may or may not be the same as the second size of therecesses in the second recess configuration 1164. For instance, thesecond size may be smaller than the first size.

A recess in any one of the recess configurations described in theembodiments of FIGS. 3 through 12B may have any one of thecross-sectional shapes illustrated in FIGS. 13A and 13B.

Additionally, as shown in FIGS. 13A and 13B, the EM wave launcher 1132may be fabricated with a stepped mating surface having a first matingsurface 1152 and a second mating surface 1154. The stepped matingsurface may be configured to couple with the slot antenna. The EM wavelauncher 1132 may comprise an edge wall extension 1156 located near aperiphery of the resonator plate 1150 and configured to couple with theprocess chamber wall. Furthermore, the EM wave launcher 1132 maycomprise an opening 1058 and a gas passage 1159. The opening 1058 may beconfigured to receive fastening devices for securing a gas line throughthe inner conductor of the EM wave launcher 1132 to the gas passage 1159in resonator plate 1150. Although only one gas passage is shown,additional gas passages may be fabricated in the resonator plate 1150.Moreover, although the shape of the gas passage is straight having acylindrical cross-section, it may be arbitrary, e.g., helical having anarbitrary cross-section. Any one or more of these features described inFIGS. 13A and 13 B may be implemented in any one of the embodimentsdescribed in FIGS. 3 through 12B.

Using the design criteria set forth in the embodiments described inFIGS. 3 through 13, these embodiments and combinations thereof may bedesigned to produce stable, uniform plasma for a process windowextending from pressures of 2 mtorr to 1 torr and powers up to 5 kW(e.g., 0.5 kW to 5 kW). The electron temperature achieved at thesubstrate plane may be about 1 eV. The relatively smaller recesses maydischarge more readily at relatively high pressure, while the relativelylarger recesses may discharge more readily at relatively low pressure.Additionally, the relatively smaller recesses may absorb excess powerwhen the relatively larger recesses saturate. In these configurations,the plasma discharge may stabilize while natural EM modes may lockand/or break up. Thus, a stable discharge may be observed near the EMwave launcher and uniform plasma properties may be observed near thesubstrate plane within the above identified process window.

Although not shown in any one of the embodiments provided in FIGS. 3through 13, one or more recesses in a recess configuration may beinterconnected. Additionally, one or more recesses of one recessconfiguration may be interconnected with one or more recesses of anotherrecess configuration. For example, one or more recesses may beinterconnected or linked by a groove or channel.

Referring now to FIGS. 14A and 14B, exemplary data for a SWP source isprovided. The SWP source comprises an EM wave launcher having a plasmasurface composed of a planar surface with a first recess configuration,a second recess configuration, and a third recess configuration. Thefirst recess configuration comprises a plurality of cylindrical recesseslocated near an outer region of the plasma surface. The second recessconfiguration comprises a plurality of cylindrical recesses located neara mid-radius region of the plasma surface. The third recessconfiguration comprises a plurality of cylindrical recesses located nearan inner region of the plasma surface.

The first recess configuration is substantially aligned with a firstplurality of slots, the second recess configuration is partly alignedwith a second plurality of slots, and the third recess configuration isnot aligned with the first plurality of slots or the second plurality ofslots. The first plurality of slots and the second plurality of slotsmay be arranged in pairs, wherein each of the pair of slots comprises afirst slot oriented orthogonal to a second slot.

As shown in FIGS. 14A and 14B, plasma ion density (n_(i), cm⁻³) wasmeasured for three regions as a function of location (z, in mm(millimeters)) across a plasma space extending from the planar surface(labeled as “FLAT” at z=0 mm) to a substrate (labeled as “SUBSTRATE” atz=130 mm). For locations where recess was present, the measurementsextend to approximately z=−15 mm (labeled as “RECESS”). A first set ofdata (open squares) was acquired in a first region that extends fromwithin a recess of the second recess configuration (e.g., partly alignedwith a slot in the slot antenna) to the substrate. A second set of data(open circles) was acquired in a second region that extends from withina recess of the third recess configuration (e.g., not aligned with aslot in the slot antenna) to the substrate. A third set of data (crossedsquares) was acquired in a third region that extends from the planarsurface to the substrate. The measurement of plasma ion density wasachieved using a Langmuir probe.

In FIG. 14A, the three sets of data were acquired for a pressure of 500mtorr (millitorr), a power of 2000 W (Watts), and a flow rate of 700sccm (standard cubic centimeters per minute). In FIG. 14B, the threesets of data were acquired for a pressure of 40 mtorr (millitorr), apower of 2000 W (Watts), and a flow rate of 700 sccm (standardcentimeters per minute). At 500 mtorr (FIG. 14A), the plasma ion densityincreased as the probe extended into the respective recess for both thesecond recess configuration and the third recess configuration. At 40mtorr (FIG. 14B), the ion density increased as the probe extended intothe recesses of the second recess configuration and decreased as theprobe extended into the recesses of the third recess configuration.

The recesses of the first recess configuration exhibit a relatively“full bright” glow across a range of power and a range of pressure(i.e., 40 mTorr to 500 mTorr). The recesses of the second recessconfiguration exhibit a relatively “bright” glow across a range of powerand a range of pressure (i.e., 40 mTorr to 500 mTorr). The recesses ofthe third recess configuration exhibit a variation from a relatively“dim” glow to a “bright” glow depending on the power and pressure (i.e.,40 mTorr to 500 mTorr). In the latter, the plasma ion density (andplasma “brightness”) increases with increasing pressure, and stabilizesthe “full bright” glow associated with the first recess configuration.To the contrary, the “FLAT” regions of the planar surface remainrelatively “dark”, and the plasma ion density increases as themeasurement extends into the plasma space. The three sets of data mergeat about 30 to 50 mm into the plasma space, and then decay uniformly tothe substrate.

Measurements and simulations (not shown) for each of the three regionshave been performed to determine the variation of the electrontemperature (T_(e)) and the electron energy probability distributionfunction (EEPf) as a function of position across the plasma spaceextending from the plasma surface to the substrate. The EEPf of theplasma spatially evolves from plasma characterized by an electron beamcomponent and a single Maxwellian component in the plasma generationzone adjacent the plasma surface, to plasma characterized by an electronbeam component and a bi-Maxwellian component, to plasma characterized bya bi-Maxwellian component, to a single Maxwellian component adjacent thesubstrate. For all three regions, the plasma evolves to a quiescentplasma having a single Maxwellian component characterized by a lowelectron temperature.

Although only certain embodiments of this invention have been describedin detail above, those skilled in the art will readily appreciate thatmany modifications are possible in the embodiments without materiallydeparting from the novel teachings and advantages of this invention.Accordingly, all such modifications are intended to be included withinthe scope of this invention.

What is claimed is:
 1. A surface wave plasma (SWP) source, comprising:an electromagnetic (EM) wave launcher configured to couple EM energy toa plasma by generating a surface wave on a plasma surface of said EMwave launcher adjacent said plasma, said EM wave launcher comprises aslot antenna having at least one slot formed therethrough configured tocouple said EM energy from a first region above said slot antenna to asecond region below said slot antenna; a resonator plate positioned insaid second region and having a lower surface of said resonator plateincluding said plasma surface of the EM wave launcher, wherein saidresonator plate comprises a plate having a plate diameter and a platethickness; a first recess configuration formed in said plasma surface,said first recess configuration having at least one first recesscharacterized by a first shape and a first size; a second recessconfiguration formed in said plasma surface, said second recessconfiguration having at least one second recess characterized by asecond shape and a second size; and a power coupling system coupled tosaid EM wave launcher and configured to provide said EM energy to saidEM wave launcher for forming said plasma, wherein said EM energycomprises an effective wavelength (λ) of propagation in said resonatorplate, and wherein said at least one first recess differs from said atleast one second recess in size, or shape, or size and shape.
 2. The SWPsource of claim 1, wherein said first size is characterized by a firstwidth and a first depth, said first width and said first depth range insize from about a quarter said effective wavelength (λ/4) to about halfsaid effective wavelength (λ/2), and wherein said second size ischaracterized by a second width and a second depth, said second widthand said second depth range in size from about a quarter said effectivewavelength (λ/4) to about half said effective wavelength (λ/2).
 3. TheSWP source of claim 1, wherein said first recess configurationcomprises: at least one first recess characterized by a first width anda first depth, said at least one first recess having a cylindricalgeometry, a conical geometry, a frusto-conical geometry, a sphericalgeometry, an aspherical geometry, a rectangular geometry, or a pyramidalgeometry, or a first annular shelf, said first annular shelf beingcharacterized by a first shelf depth and first shelf width, or a firstannular channel, said first annular channel being characterized by afirst channel depth, a first inner channel radius, and a first outerchannel radius, or a combination of two or more thereof.
 4. The SWPsource of claim 3, wherein: said first width ranges in size from about aquarter said effective wavelength (λ/4) to about half said effectivewavelength (λ/2); and said first depth, a first difference between saidplate thickness and said first depth, said first shelf depth, or saidfirst channel depth ranges in size from about a quarter said effectivewavelength (λ/4) to about half said effective wavelength (λ/2).
 5. TheSWP source of claim 3, wherein said second recess configurationcomprises: at least one second recess characterized by a second widthand a second depth, said at least one second recess having a cylindricalgeometry, a conical geometry, a frusto-conical geometry, a sphericalgeometry, an aspherical geometry, a rectangular geometry, or a pyramidalgeometry, or a second annular shelf, said second annular shelf beingcharacterized by a second shelf depth and a second shelf width, or asecond annular channel, said second annular channel being characterizedby a second channel depth, a second inner channel radius, and a secondouter channel radius, or a combination of two or more thereof.
 6. TheSWP source of claim 5, wherein: said second width ranges in size fromabout a quarter said effective wavelength (λ/4) to about half saideffective wavelength (λ/2); and said second depth, a second differencebetween said plate thickness and said second depth, said second shelfdepth, or said second channel depth ranges in size from about a quartersaid effective wavelength (λ/4) to about half said effective wavelength(λ/2).
 7. The SWP source of claim 1, wherein: said power coupling systemcomprises a coaxial feed for coupling EM energy to said EM wavelauncher, and said slot antenna comprises one end coupled to an innerconductor of said coaxial feed and another end coupled to an outerconductor of said coaxial feed.
 8. The SWP source of claim 1, whereinsaid EM wave launcher further comprises: a slow wave plate positioned insaid first region and configured to reduce said effective wavelength ofsaid EM energy relative to a wavelength of said EM energy in free space.9. The SWP source of claim 8, wherein said slow wave plate and saidresonator plate each consist essentially of quartz or a high dielectricconstant (high-k) material, said high dielectric constant materialhaving a dielectric constant greater than a value of
 4. 10. The SWPsource of claim 1, wherein said power coupling system comprises: amicrowave source configured to produce microwave energy at 2.45 GHz; awaveguide coupled to an outlet of said microwave source; an isolatorcoupled to said waveguide and configured to prevent propagation ofmicrowave energy back to said microwave source; and a coaxial convertercoupled to said isolator and configured to couple said microwave energyto a coaxial feed, wherein said coaxial feed is further coupled to saidEM wave launcher.
 11. The SWP source of claim 1, wherein said at leastone slot includes a plurality of slots that are arranged in pairs, andwherein each of said pair of slots comprises a first slot orientedorthogonal to a second slot.
 12. The SWP source of claim 1, wherein saidfirst recess configuration is located near an outer region of saidplasma surface.
 13. The SWP source of claim 1, wherein said secondrecess configuration is located near an inner region of said plasmasurface.
 14. The SWP source of claim 1, wherein said plate thickness isabout half said effective wavelength (λ/2).
 15. The SWP source of claim5, wherein: said plate thickness ranges from about 25 mm to about 45 mm;said first width ranges from about 25 mm to about 35 mm; said secondwidth ranges from about 25 mm to about 35 mm, said first depth, a firstdifference between said plate thickness and said first depth, said firstshelf depth, or said first channel depth ranges from about 10 mm toabout 35 mm; and said second depth, a second difference between saidplate thickness and said second depth, said second shelf depth, or saidsecond channel depth ranges from about 10 mm to about 35 mm.
 16. The SWPsource of claim 15, wherein said second width is less than said firstwidth.
 17. The SWP source of claim 3, further comprising: at least onethird recess formed at a bottom of said first annular shelf or at abottom of said first annular channel, said at least one third recessbeing characterized by a third depth and a third diameter.
 18. The SWPsource of claim 17, wherein a third difference between said platethickness and said third depth is about quarter said effectivewavelength (λ/4).
 19. A surface wave plasma (SWP) source, comprising: anelectromagnetic (EM) wave launcher configured to couple EM energy in adesired EM wave mode to a plasma in a process space by generating asurface wave on a plasma surface of said EM wave launcher adjacent saidplasma, said EM wave launcher comprises a slot antenna having at leastone slot formed therethrough configured to couple said EM energy from afirst region above said slot antenna to a second region below said slotantenna, and a resonator plate positioned in said second region andhaving a lower surface of said resonator plate including said plasmasurface of the EM wave launcher; a first recess configuration formed insaid plasma surface; means for uniformly generating said plasma in saidprocess space, said means for stabilizing said plasma being formed insaid plasma surface of said resonator plate; and a power coupling systemcoupled to said EM wave launcher and configured to provide said EMenergy to said EM wave launcher for forming said plasma.
 20. The SWPsource of claim 19, further comprising: means for stabilizing saidplasma for a pressure in said process space, said means for stabilizingsaid plasma being formed in said plasma surface of said resonator plate,wherein said pressure ranges from about 2 mtorr to about 1 torr.